Differential sensitivity of human mammary epithelial and breast carcinoma cell lines to curcumin

Evaluating the effects of curcumin nano-chitosan on miR-221 and miR-222 expression and Wnt/β-catenin pathways in MCF-7, MDA-MB-231 and SKBR3 cell lines

BACKGROUND

Breast cancer is one of the most common diseases worldwide that affects women of reproductive age. miR-221 and miR-222 are two highly homogeneous microRNAs that play pivotal roles in many cellular processes and regulate the Wnt/β-catenin signaling pathway. Curcumin (CUR), a yellow polyphenolic compound, targets numerous signaling pathways relevant to cancer therapy. The main aim of this study was to compare the ability of chitosan curcumin nanoparticle (CC-CUR) formulation with the curcumin in modulating miR-221 and miR-222 expression through Wnt/β-catenin signaling pathway in MCF-7, MDA-MB-231 and SK-BR-3 breast cancer cell lines.

METHOD

Chitosan-cyclodextrin-tripolyphosphate containing curcumin nanoparticles (CC-CUR) were prepared. Cytotoxicity of the CUR and CC-CUR was evaluated. Experimental groups including CC-CUR, CUR and negative control were designed. The expression of miR-221 and miR-222 and Wnt/β-catenin pathway genes was measured.

RESULTS

The level of miR-221 and miR-222 and β-catenin genes decreased in MCF-7 and MDA-MB-231 cells and WIF1 gene increased in all cells in CC-CUR group. However, the results in SK-BR-3 cell line were unexpected; since miRs and WIF1 gene expressions were increased following CC-CUR administration and β-catenin decreased by administration of CUR.

CONCLUSION

Although the composite form of curcumin decreased the expression of miR-221 and miR-222 in MCF-7 and MDA cells, with significant decreasing of β-catenin and increasing of WIF1 gene in almost all three cell lines, we can conclude than this formulation exerts its effect mainly through the Wnt/β-catenin pathway. These preliminary findings may pave the way for the use of curcumin nanoparticles in the treatment of some known cancers.

The Apoptotic Activity of Curcumin Against Oral Cancer Cells Without Affecting Normal Cells in Comparison to Paclitaxel Activity

Until now, chemotherapy, which has a series of side effects, has been the most widely employed treatment for different types of cancer. However, bioactive products have been utilized as alternative medicines for tumors due to their bioactivities with low or no side effects in normal cells. This research reported for the first time that curcumin (CUR) and paclitaxel (PTX) have significant anti-cancer activity against normal human gingival fibroblast (HGF) and tongue squamous cell carcinoma fibroblast (TSCCF) cell lines. The results showed that CUR (13.85 µg mL^-1) and PTX (8.17 µg mL^-1) significantly inhibited TSCCF cell viability, with no significant effect on normal HGF cells. SEM showed morphological changes in cells treated with CUR and PTX, especially with TSCCF cells, compared to HGF normal cells. For TSCCF, the results showed the highest necrosis was achieved with CUR (58.8%) and PTX (39%) as compared to the control (2.99%). For normal HGF cells, the highest early and late apoptosis was achieved with PTX. Further, DCFH-DA analyses showed no significant ROS stimulation in TSCCF and HGF cell lines treated with CUR and PTX. The ¹H NMR analysis results show the presence of methoxy and hydroxyl groups and aromatic hydrogens in the CUR structure. In conclusion, the results confirmed that CUR is more specific to the oral cancer cells but not normal cells by inducing apoptosis in a dose- and time-dependent manner, with decreased TSCCF cell viability, and the cytotoxicity of CUR and PTX is not through the ROS pathway.

Curcumin: reclaiming the lost ground against cancer resistance

Curcumin, a polyphenol, has a wide range of biological properties such as anticancer, antibacterial, antitubercular, cardioprotective and neuroprotective. Moreover, the anti-proliferative activities of Curcumin have been widely studied against several types of cancers due to its ability to target multiple pathways in cancer. Although Curcumin exhibited potent anticancer activity, its clinical use is limited due to its poor water solubility and faster metabolism. Hence, there is an immense interest among researchers to develop potent, water-soluble, and metabolically stable Curcumin analogs for cancer treatment. While drug resistance remains a major problem in cancer therapy that renders current chemotherapy ineffective, curcumin has shown promise to overcome the resistance and re-sensitize cancer to chemotherapeutic drugs in many studies. In the present review, we are summarizing the role of curcumin in controlling the proliferation of drug-resistant cancers and development of curcumin-based therapeutic applications from cell culture studies up to clinical trials.

Anticancer properties of medicinal plants and their bioactive compounds against breast cancer: a review on recent investigations

Breast cancer (BC) is one of the most common and recurring diseases and the second leading cause of death in women. Despite prevention, diagnostics, and therapeutic options such as radiation therapy and chemotherapy, the number of occurrences increases every year. Therefore, novel therapeutic drugs targeting specifically different checkpoints should be developed against breast cancer. Among drugs that can be developed to treat breast cancer, natural products, such as plant-derived compounds, showed significant anti-breast cancer properties. These substances belong to different chemical classes such as flavonoids, terpenoids, phenolic acids, and alkaloids. They exert their in vitro and in vivo cytotoxic activities against breast cancer cell lines via different mechanisms, including the inhibition of extrinsic and intrinsic apoptotic pathways, the arrest of the cell cycle, and the activation of autophagy. Moreover, they also exhibit anti-angiogenesis and antimetastatic action. Moreover, chemoprevention effects of these bioactive compounds were signaled only for certain drugs. Therefore, the aim of this review is to highlight the pharmacological actions of medicinal plants and their bioactive compounds on breast cancer. Moreover, the role of these substances in breast cancer chemoprevention was also discussed.

Biomedical Applications and Bioavailability of Curcumin-An Updated Overview

Curcumin, a yellow-colored molecule derived from the rhizome of Curcuma longa, has been identified as the bioactive compound responsible for numerous pharmacological activities of turmeric, including anticancer, antimicrobial, anti-inflammatory, antioxidant, antidiabetic, etc. Nevertheless, the clinical application of curcumin is inadequate due to its low solubility, poor absorption, rapid metabolism and elimination. Advancements in recent research have shown several components and techniques to increase the bioavailability of curcumin. Combining with adjuvants, encapsulating in carriers and formulating in nanoforms, in combination with other bioactive agents, synthetic derivatives and structural analogs of curcumin, have shown increased efficiency and bioavailability, thereby augmenting the range of applications of curcumin. The scope for incorporating biotechnology and nanotechnology in amending the current drawbacks would help in expanding the biomedical applications and clinical efficacy of curcumin. Therefore, in this review, we provide a comprehensive overview of the plethora of therapeutic potentials of curcumin, their drawbacks in efficient clinical applications and the recent advancements in improving curcumin's bioavailability for effective use in various biomedical applications.

Do natural ingredients in a dentifrice contribute to prevention of plaque and gingivitis?

OBJECTIVE

To test the effectiveness of a dentifrice containing the turmeric and licorice extract compared to a control for preventing plaque and gingivitis over a four-month period.

MATERIAL AND METHODS

Ninety (non-dental) participants with moderate gingival inflammation(≥40%) were selected. The triple blind study consisted of two phases, namely at first a 3-week pre-experimental phase of using an oxygenating and chlorhexidine (CHX) mouthrinse. Secondly, a 4-months experimental period in which participants were randomly assigned to a test or control group. All were instructed to brush their teeth twice daily for 2 minutes with their assigned dentifrice. Gingival bleeding(BI), plaque(PI) and gingivitis(GI) were assessed.

RESULTS

Eighty participants completed the protocol. At the first assessment in the pre-experimental phase, the mean scores of all indices showed no differences for the two groups. At the second session, the values of all three parameters had decreased significantly (p<0.001). At the last session the BI values were 0.52(0.25) for the test group and 0.56(0.25) for the control, the mean GI was 0.27(0.17) for the test group and 0.31 0.16) for the control, and for PI the scores were 1.89(0.46) for the test group and 1.98(0.43) for the control group. Statistical comparison of the scores for the two groups at each stage of the study showed no significant difference for any of the parameters.

CONCLUSION

Within the limits of the current study design, dentifrice formulation and concentration of turmeric/licorice extracts the results show that the adjuvant effect of the natural ingredients in the test dentifrice was not evident on clinical parameters of gingivitis and plaque.

Natural substances in cancer—do they work?

Owing to anticancer properties of selected natural substances, it is assumed that they have potential to be used in oncological therapy. Here, the recently proven effects of the selected natural polyphenols, resveratrol and curcumin, are described. Secondly, the potential of probiotics and prebiotics in modulation of immunological response and/or enhancing the chemotherapeutic treatments is reported based on the recent clinical trials. Further, the chapter presents current knowledge regarding the targeted supplementation of the patient with probiotic bacteria and known efficacy of probiotics to support immunotherapy. The major clinical trials are listed, aiming to verify whether, and to which extent the manipulation of patient’s microbiome can improve the outcome of chemotherapies. In the end, a potential of natural substances and feed ingredients to pose epigenetic changes is highlighted. The chapter provides an insight into the scientific proofs about natural bioactive substances in relation to cancer treatment, leaded by the question – do they really work?

Ras Signaling in Breast Cancer

Ras proteins mediate extracellular and cytoplasmic signaling networks via receptor tyrosine kinase. The Ras pathway induces activation of signaling molecules involved in cell proliferation and growth, cell survival and apoptosis, metabolism, and motility. Although Ras mutations in breast cancer are not frequently reported, hyperactivation of Ras signaling plays an important role in breast cancer growth and progression. Oncogenic Ras activation occurs via loss of Ras GTPase-activating proteins, overexpression of growth factor receptor, and stimulation by various cytokines. Effective control of oncogenic Ras is one of the therapeutic strategies in breast cancer. The mechanisms of intracellular localization, activation, and signaling pathway of Ras in cancer have been used to develop therapeutic candidates. Recent studies have reported an effective therapy for breast cancer by inhibition of enzymes involved in the posttranslational modification of Ras, such as farnesyltransferase and geranylgeranyltransferase 1, and anti-cancer therapies targeting the epidermal growth factor receptor (EGFR). Emerging targets involved in EGF-mediated Ras activity in breast cancer have shed new insight into Ras activation in breast cancer progression. These alternative mechanisms for Ras signaling pathway may suggest novel therapeutic approaches for targeting Ras in breast cancer. In spite of the difficulties in targeting Ras protein, important discoveries highlight the direct inhibition of Ras activity. Further studies may elucidate the effects of targeting Ras protein and the clinical relevance thereof.

Effects of Photosensitization of Curcumin in Human Glioblastoma Multiforme Cells

BACKGROUND/AIM

There is no satisfactory treatment of glioblastoma multiforme, a highly invasive brain tumor. The aim of this study was to analyze the cytotoxic effects of curcumin (CUR) alone and as a photosensitizer on glioblastoma cells.

MATERIALS AND METHODS

The SNB-19 cells where incubated for 2 and 24 h with 5-200 mM of CUR. The cells were radiated with blue light (6 J/cm²) and compared to non-irradiated ones. The effects of treatment were assessed by measuring mitochondrial activity with the MTT method and apoptosis progression by flow cytometry. To investigate CUR uptake, fluorescence imaging of cells was performed.

RESULTS

Photosensitization of CUR decreased the EC₅₀ 6.3 times when the incubation time was 2 h and over 90% of cells underwent apoptosis. The study of the uptake of CUR showed that during the 2 h, CUR was placed in the entire cytoplasm, and over time, its amount decreased and localized in the subcellular compartments.

CONCLUSION

CUR is a promising medicament that can be used as a photosensitizer in photodynamic therapy for glioma treatment.

Bioactive Compounds: Multi-Targeting Silver Bullets for Preventing and Treating Breast Cancer

Each cell in our body is designed with a self-destructive trigger, and if damaged, can happily sacrifice itself for the sake of the body. This process of self-destruction to safeguard the adjacent normal cells is known as programmed cell death or apoptosis. Cancer cells outsmart normal cells and evade apoptosis and it is one of the major hallmarks of cancer. The cardinal quest for anti-cancer drug discovery (bioactive or synthetic compounds) is to be able to re-induce the so called “programmed cell death” in cancer cells. The importance of bioactive compounds as the linchpin of cancer therapeutics is well known as many effective chemotherapeutic drugs such as vincristine, vinblastine, doxorubicin, etoposide and paclitaxel have natural product origins. The present review discusses various bioactive compounds with known anticancer potential, underlying mechanisms by which they induce cell death and their preclinical/clinical development. Most bioactive compounds can concurrently target multiple signaling pathways that are important for cancer cell survival while sparing normal cells hence they can potentially be the silver bullets for targeting cancer growth and metastatic progression.

Zebularine and trichostatin A sensitized human breast adenocarcinoma cells towards tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-induced apoptosis

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising cancer therapeutic agent due to its selective killing on cancer cells while sparing the normal cells. Nevertheless, breast adenocarcinoma cells can develop TRAIL resistance. Therefore, this project investigated the anti-cancer effects of the combination of epigenetic drugs zebularine and trichostatin A (ZT) with TRAIL (TZT) on the human breast adenocarcinoma cells. This treatment regimen was compared with the natural anti-cancer compound curcumin (Cur) and standard chemotherapeutic drug doxorubicin (Dox). As compared to TRAIL treatment, TZT treatment hampered the cell viability of human breast adenocarcinoma cells MDA-MB-231 significantly but not MCF-7 and immortalized non-cancerous human breast epithelial cells MCF10A. Unlike TZT, Cur and Dox treatments reduced cell viability in both human breast adenocarcinoma and epithelial cells significantly. Nevertheless, there were no changes in cell cycle in both TRAIL and TZT treatments in breast adenocarcinoma and normal epithelial cells. Intriguingly, Cur and Dox treatment generally induced G2/M arrest in MDA-MB-231, MCF-7 and MCF10A but Cur induced S phase arrest in MCF10A. The features of apoptosis such as morphological changes, apoptotic activity and the expression of cleaved poly (ADP) ribose polymerase (PARP) protein were more prominent in TRAIL and TZT-treated MDA-MB-231 as compared to MCF10A at 24 h post-treatment. Compared to TZT treatment, Cur and Dox treatments exhibited lesser apoptotic features in MDA-MB-231. Collectively, the sensitization using Zeb and TSA to augment TRAIL-induced apoptosis might be an alternative therapy towards human breast adenocarcinoma cells, without harming the normal human breast epithelial cells.

Role of curcumin in regulating p53 in breast cancer: an overview of the mechanism of action

p53 is a tumor suppressor gene involved in various cellular mechanisms including DNA repair, apoptosis, and cell cycle arrest. More than 50% of human cancers have a mutated nonfunctional p53. Breast cancer (BC) is one of the main causes of cancer-related deaths among females. p53 mutations in BC are associated with low survival rates and more resistance to the conventional therapies. Thus, targeting p53 activity was suggested as an important strategy in cancer therapy. During the past decades, cancer research was focused on the development of monotargeted anticancer therapies. However, the development of drug resistance by modulation of genes, proteins, and pathways was the main hindrance to the success of such therapies. Curcumin is a natural product, extracted from the roots of Curcuma longa, and possesses various biological effects including anticancer activity. Previous studies proved the ability of curcumin to modulate several signaling pathways and biomolecules in cancer. Safety and cost-effectiveness are additional inevitable advantages of curcumin. This review summarizes the effects of curcumin as a regulator of p53 in BC and the key molecular mechanisms of this regulation.

Phyto-polyphenols as potential inhibitors of breast cancer metastasis

Breast cancer is the most common cancer among women as metastasis is currently the main cause of mortality. Breast cancer cells undergoing metastasis acquire resistance to death signals and increase of cellular motility and invasiveness.Plants are rich in polyphenolic compounds, many of them with known medicinal effects. Various phyto-polyphenols have also been demonstrated to suppress cancer growth. Their mechanism of action is usually pleiotropic as they target multiple signaling pathways regulating key cellular processes such as proliferation, apoptosis and differentiation. Importantly, some phyto- polyphenols show low level of toxicity to untransformed cells, but selective suppressing effects on cancer cells proliferation and differentiation.In this review, we summarize the current information about the mechanism of action of some phyto-polyphenols that have demonstrated anti-carcinogenic activities in vitro and in vivo. Gained knowledge of how these natural polyphenolic compounds work can give us a clue for the development of novel anti-metastatic agents.

Intracellular self-disassemble polysaccharide nanoassembly for multi-factors tumor drug resistance modulation of doxorubicin

Drug efflux induced by multidrug resistance (MDR) overexpression, as well as secondary drug resistance caused by subtoxic drug microenvironments as a result of inefficient drug release of nanoscopic drug carriers in tumor cells, are major bottlenecks for chemotherapy.

Concentration- Dependent Effects of Curcumin on 5-Fluorouracil Efficacy in Bladder Cancer Cells

Purpose: Curcumin (Cur), a herbal ingredient with anticancer properties, has been shown to inhibit growth of malignant cells in vivo and in vitro. However, studies on combination therapy of Cur with chemotherapeutic drugs have been limited. Here, effects of Cur on the cytotoxicity of 5-Fluorouracil (FU) were investigated with epithelial bladder cancer cells (EJ138) in vitro. Methods: EJ138 cells were treated with 5 and 15 μM of Cur and/ or 100 μM of FU. Cell viability was measured by sulforhodamine B colorimetric assay. The glucose concentration as an index of cell metabolism was evaluated by an enzymatic method. Total oxidant and antioxidant capacities were estimated by the ferrous oxidation-xylenol (FOX1) method and ferric reducing antioxidant power assay (FRAP), respectively. Results: Combination of 5 μM Cur with FU significantly reduced its cytotoxicity in EJ138 cells, while 15 μM Cur caused an opposite increase. Significant increase in glucose concentration at 24 h and decrease in the FRAP value at 48 h incubation was observed in cells treated with FU in combination with Cur. There were no significant changes in total oxidant capacity with the combination therapy. Conclusion: Our findings suggest a crucial role of Cur concentration in regulating chemotherapeutic agent-induced cytotoxicity. Further investigations are needed to understand the precise mechanisms of action of Cur and determine appropriate doses with combination therapy for clinical application against human cancers.

Curcumin-loaded nanoliposomes linked to homing peptides for integrin targeting and neuropilin-1-mediated internalization

CONTEXT

Curcumin, a naturally occurring polyphenol, has been extensively studied for its broad-spectrum anticancer effects. The potential benefits are, however, limited due to its poor water solubility and rapid degradation which result in low bioavailability on administration.

OBJECTIVES

This study encapsulates curcumin in nanoliposomes including an integrin-homing peptide combined with a C end R neuropilin-1 targeting motif for targeted delivery and receptor-mediated internalization, respectively.

MATERIALS AND METHODS

The linear GHHNGR (Glycine-Histidine-Histidine-Asparagine-Glycine-Arginine) was synthesized through F-moc chemistry on 2-chlorotrityl chloride resin and conjugated to oleic acid. The lipoyl-peptide units were then co-assembled with lecithin and 0-75 mole % Tween-80 into liposomes. Curcumin was passively entrapped using a film hydration technique and its degradation profile was examined within seven consecutive days. The cytotoxic effects of the curcumin-loaded liposomes were studied on MCF-7 and MDA-MB-468, during 24 h exposure in MTT assay.

RESULTS

The maximum curcumin entrapment (15.5% W/W) and minimum degradation (< 23%) were obtained in a pH switch loading method from 5.7 to 8, in nanoliposomes (< 50 nm) containing oleyl-peptide, lecithin and Tween-80 (1:1:0.75 mole ratio). The oleyl-peptide did not prove any haemolytic activity (< 1.5%) up to 10-fold of its experimental concentration. The curcumin-loaded liposomes displayed significant reduction in the viabilities of MCF-7 (IC₅₀ 3.8 μM) and MDA-MB-468 (IC₅₀ 5.4 μM).

DISCUSSION AND CONCLUSION

This study indicated potential advantages of the peptide-conjugated liposomes in drug transport to the cancer cells. This feature might be an outcome of probable interactions between the targeted nanoliposomes with the integrin and neuropilin-1 receptors.

Curcumin-mediated anti-microbial photodynamic therapy against Candida dubliniensis biofilms

The purpose of this study was to evaluate the effectiveness of anti-microbial photodynamic therapy (aPDT) mediated by curcumin (Cur) associated with LED light against biofilms of Candida dubliniensis, and further, investigate cellular uptake and drug penetration through the biofilms under confocal laser scanning microscopy (CLSM). Four C. dubliniensis strains were tested: three clinical isolates from HIV-positive patients and one reference strain (CBS 7987). Biofilms were treated with three Cur concentrations (20.0, 30.0, and 40.0 μM). All samples were incubated in the dark for 20 min and exposed to a 5.28 J/cm² of LED light fluence. Additional samples of each strain were treated either with Cur or LED light only. Control samples had neither Cur nor light. After aPDT, results were read using the XTT salt reduction method. The data were statistically analyzed by two-way ANOVA followed by Games-Howell post-hoc test (α = 0.05). Confocal laser scanning microscopy was used to verify both the uptake of Cur by yeast cells and its penetration through the biofilm. The results showed that aPDT promoted significant reduction on the metabolism of the biofilm-organized cells of C. dubliniensis. Further, while Cur was rapidly taken up by C. dubliniensis cells, a longer time interval was required to allow Cur penetration into biofilm cells. Based on these results, aPDT associating LED and Cur presents promising potential on fungal control of biofilms of C. dubliniensis.

Metastatic genes targeted by an antioxidant in an established radiation- and estrogen-breast cancer model

Breast cancer remains the second most common disease worldwide. Radiotherapy, alone or in combination with chemotherapy, is widely used after surgery as a treatment for cancer with proven therapeutic efficacy manifested by reduced incidence of loco-regional and distant recurrences. However, clinical evidence indicates that relapses occurring after radiotherapy are associated with increased metastatic potential and poor prognosis in the breast. Among the anticarcinogenic and antiproliferative agents, curcumin is a well-known major dietary natural yellow pigment derived from the rhizome of the herb Curcuma longa (Zingiberaceae). The aim of the present study was to analyze the differential expression of metastatic genes in radiation- and estrogen-induced breast cancer cell model and the effect of curcumin on such metastatic genes in breast carcinogenesis. Expression levels of TGF-α and TGFβ1 genes were upregulated in MCF-10F and downregulated in Tumor2 cell lines treated with curcumin. Expression levels of other genes such as caspase 9 and collagen 4 A2 were upregulated in both MCF-10F and Tumor2-treated cell lines. Integrin α5 and cathepsin B and D decreased its expression in Tumor2, whereas E-Cadherin, c-myc and CD44 expressions were only increased in MCF-10F. It can be concluded that metastatic genes can be affected by curcumin in cancer progression and such substance can be used in breast cancer patients with advanced disease without side-effects commonly observed with therapeutic drugs.

Curcumin inhibits MCF-7 cells by modulating the NF-κB signaling pathway

The present study investigated the inhibitory effect of curcumin on human breast cancer MCF-7 cells and investigated the potential underlying molecular mechanisms. MCF-7 cells were cultured with curcumin at different concentrations and time points. The effects of curcumin treatment on breast cancer cell proliferation were studied using a MTT assay. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to assess the mRNA and protein expression levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax), nuclear factor-κ-light-chain-enhancer of activated B cells (NF-κB) and inhibitor of NF-κB-α (IκBα). The proliferation of MCF-7 cells in the group treated with curcumin was markedly decreased compared with the control, with the greatest inhibitory effect at a concentration of 20 µM. The expression of Bax mRNA was increased and Bcl-2 mRNA expression was decreased compared with the control. Additionally, protein expression of NF-κB and IκB was increased. The data indicate that curcumin is able to inhibit breast cancer cell proliferation, possibly by regulating the NF-κB signaling pathway.

Cucurmin, anticancer, & antitumor perspectives: A comprehensive review

Cucurmin, a naturally yellow component isolated from turmeric, ability to prevent various life-style related disorders. The current review article mainly emphasizes on different anticancer perspectives of cucurmin, i.e., colon, cervical, uterine, ovarian, prostate head and neck, breast, pulmonary, stomach and gastric, pancreatic, bladder oral, oesophageal, and bone cancer. It holds a mixture of strong bioactive molecule known as cucurminoids that has ability to reduce cancer/tumor at initial, promotion and progression stages of tumor development. In particular, these compounds block several enzymes required for the growth of tumors and may therefore involve in tumor treatments. Moreover, it modulates an array of cellular progressions, i.e., nitric oxide synthetase activity, protein kinase C activity, epidermal growth factor (EGF) receptor intrinsic kinase activity, nuclear factor kappa (NF-kB) activity, inhibiting lipid peroxidation and production of reactive oxygen species. However, current manuscript summarizes most of the recent investigations of cucurmin but still further research should be conducted to explore the role of curcumin to mitigate various cancers.

Assessment of Cytotoxicity Profiles of Different Phytochemicals: Comparison of Neutral Red and MTT Assays in Different Cells in Different Time Periods

Objectives

Phenolic compounds exhibit several health protective properties. Galangin, curcumin, pycnogenol, puerarin and ursolic acid are commonly used plant phenolics in folk medicine. The aim of our study was to evaluate the difference between neutral red uptake (NRU) and MTT assays using different plant phenolics (galangin, curcumin, pycnogenol, puerarin and ursolic acid) in healthy and cancer cells in different time periods.

Materials and Methods

In this study, the cytotoxic effects of these phenolic compounds were investigated by NRU and MTT assays in healthy (V79, Chinese hamster fibroblast cell line) and cancer [human cervix epithelial adenocarcinoma cell line Henrietta Lacks (HeLa) and human mammary carcinoma cell line (BT-474)] in 18, 24 and 48 h incubation periods.

Results

Our results demonstrated that galangin, curcumin, pycnogenol, puerarin and ursolic acid decreased cell viability of V79, HeLa and BT-474 cells in a dose-dependent manner in 18, 24 and 48 h incubation periods. However, the cell survival rate was much lower in 48 h incubation period. There was no difference between the results from NRU and MTT assays.

Conclusion

To decide which incubation period and which cytotoxicity study to be used, the cytotoxicity mechanism of the compound must be known.

Suppression of TAFI by siRNA inhibits invasion and migration of breast cancer cells

Human thrombin activatable fibrinolysis inhibitor (TAFI), also known as carboxypeptidase B2 (CPB2), is a procarboxypeptidase enzyme. The purpose of the present study was to observe the expression of TAFI in breast cancer (BC) and breast cancer cell (BCC) lines and to investigate the effect of TAFI suppression by small interfering (si)RNA gene silencing on invasion and migration of BCC lines. A significant increase in TAFI level was identified by immunohistochemical analysis in BC tissues compared with normal breast tissues. TAFI suppression also inhibited cell viability, invasion and migration ability as demonstrated by MTT, Transwell chamber, and wound scratch assays, respectively (P<0.05). The data suggested that suppression of TAFI by siRNA inhibits invasion and migration of breast cancer cells and that TAFI may be a new target for breast cancer therapy.

Biological and pharmacological evaluation of dimethoxycurcumin: A metabolically stable curcumin analogue with a promising therapeutic potential

Dimethoxycurcumin (DiMC) is a synthetic analog of curcumin with superior inter-related pro-oxidant and anti-cancer activity, and metabolic stability. Numerous studies have shown that DiMC reserves the biologically beneficial features, including anti-inflammatory, anti-carcinogenic, and cytoprotective properties, almost to the same extent as curcumin exhibits. DiMC lacks the phenolic-OH groups as opposed to curcumin, dimethoxycurcumin, and bis-demethoxycurcumin that all vary in the number of methoxy groups per molecule, and has drawn the attentions of researchers who attempted to discover the structure-activity relationship (SAR) of curcumin. In this regard, tetrahydrocurcumin (THC), the reduced and biologically inert metabolite of curcumin, denotes the significance of the conjugated α,β diketone moiety for the curcumin activity. DiMC exerts unique molecular activities compared to curcumin, including induction of androgen receptor (AR) degradation and suppression of the transcription factor activator protein-1 (AP-1). The enhanced AR degradation on DiMC treatment suggests it as a novel anticancer agent against resistant tumors with androgenic etiology. Further, DiMC might be a potential treatment for acne vulgaris. DiMC induces epigenetic alteration more effectively than curcumin, although both showed no direct DNA hypomethylating activity. Given the metabolic stability, nanoparticulation of DiMC is more promising for in vivo effectiveness. However, studies in this regard are still in its infancy. In the current review, we portray the various molecular and biological functions of DiMC reported so far. Whenever possible, the efficiency is compared with curcumin and the reasons for DiMC being more metabolically stable are elaborated. We also provide future perspective investigations with respect to varying DiMC-nanoparticles.

Dual release of angiostatin and curcumin from biodegradable PLGA microspheres inhibit Lewis lung cancer in a mice model

Schematic illustration of the proposed structure and mechanism of anti-cancer actions of As–Cur–PLGA-Ms.

Co-Delivery of angiostatin and curcumin by a biodegradable polymersome for antiangiogenic therapy

Illustration of the AS–Cur-loaded polymersomes formed by block polymers for antiangiogenic therapy.

Curcumin inhibits development and cell adhesion in Dictyostelium discoideum: Implications for YakA signaling and GST enzyme function

The molecular basis for nutraceutical properties of the polyphenol curcumin (Curcuma longa, Turmeric) is complex, affecting multiple factors that regulate cell signaling and homeostasis. Here, we report the effect of curcumin on cellular and developmental mechanisms in the eukaryotic model, Dictyostelium discoideum. Dictyostelium proliferation was inhibited in the presence of curcumin, which also suppressed the prestarvation marker, discoidin I, members of the yakA-mediated developmental signaling pathway, and expression of the extracellular matrix/cell adhesion proteins (DdCAD and csA). This resulted in delayed chemotaxis, adhesion, and development of the organism. In contrast to the inhibitory effects on developmental genes, curcumin induced gstA gene expression, overall GST activity, and generated production of reactive oxygen species. These studies expand our knowledge of developmental and biochemical signaling influenced by curcumin, and lends greater consideration of GST enzyme function in eukaryotic cell signaling, development, and differentiation.

Cellular Effect of Curcumin and Citral Combination on Breast Cancer Cells: Induction of Apoptosis and Cell Cycle Arrest

Purpose

The unmanageable side effects caused by current chemotherapy regimens to treat cancer are an unresolved problem. Although many phytonutrients are useful as chemoprevention without side effects, their effects are slower and smaller than conventional chemotherapy. In the present work, we examined the cumulative effect of two phytonutrients, curcumin and citral, on breast cancer cell lines and compared their effect with the known chemotherapy regimen of cyclophosphamide, methotrexate, and 5-fluorouracil.

Methods

Using cultured breast cancer and normal epithelial cells, the cytotoxic and apoptotic effect of curcumin and citral was evaluated in vitro. The synergistic effect of curcumin and citral was calculated by a combination index study using the method by Chou and Talalay. Cell death pathways and mechanisms were analyzed by measuring intracellular reactive oxygen species (ROS) and apoptotic protein levels.

Results

Curcumin and citral caused dose and time dependent cell death and showed a synergistic effect at effective concentration EC₅₀ and above concentrations in breast cancer cells without disturbing normal breast epithelial cells. With combination curcumin and citral treatment, apoptosis induction and cell cycle arrest at G0/G1 phase in breast cancer cells were observed. Curcumin and citral generated ROS and activated p53 and poly (ADP-ribose) polymerase-1 mediated apoptotic pathways.

Conclusion

The results of this study suggest that curcumin and citral in combination may be a useful therapeutic intervention for breast cancer.

Enhanced antitumor efficacy of folate targeted nanoparticles co-loaded with docetaxel and curcumin

BACKGROUND

The current study aimed to investigate whether the novel folate (FT) modified nanoparticles (NPs) co-loaded with docetaxel (DT) and curcumin (CU) (named as FT-NPs) could enhance the delivery efficiency to tumor compared with the NPs without FT (non-targeted NPs).

METHODS

FT-NPs were successfully formulated in this article. In vitro cytotoxic activity against A549 cells and in vivo antitumor activity of FT-NPs in S180 cell bearing mice were conducted. Cellular uptake test was used to evaluate uptake efficiency of FT-NPs. Histological observation was used to determine the lung security. Besides, the physical chemical properties such as stability, particle size, zeta potential, drug encapsulation efficiency, transmission electron microscopy (TEM) were also conducted.

RESULTS

FT-NPs exhibited stronger growth inhibition effects on A549 cells compared with non-targeted NPs, moreover, the novel FT-NPs indicated more effective antitumor efficacy in inhibiting tumor growth. Confocal laser scanning microscopy indicated that the uptake of FT-NPs was facilitated and effective. Histological observation meant that FT-NPs were biocompatible and appropriate for pulmonary administration.

CONCLUSION

These results confirmed that FT-NPs with relatively high drug loading capacity could effectively inhibit tumor growth and reduce toxicity. The novel FT-NPs could produce as an outstanding nanocarrier for the targeted treatment of cancers.

Curcumin: a potential candidate in prevention of cancer via modulation of molecular pathways

Cancer is the most dreadful disease worldwide in terms of morbidity and mortality. The exact cause of cancer development and progression is not fully known. But it is thought that cancer occurs due to the structural and functional changes in the genes. The current approach to cancer treatment based on allopathic is expensive, exhibits side effects; and may also alter the normal functioning of genes. Thus, a safe and effective mode of treatment is needed to control the cancer development and progression. Some medicinal plants provide a safe, effective and affordable remedy to control the progression of malignant cells. The importance of medicinal plants and their constituents has been documented in Ayurveda, Unani medicine, and various religious books. Curcumin, a vital constituent of the spice turmeric, is an alternative approach in the prevention of cancer. Earlier studies have shown the effect of curcumin as an antioxidant, antibacterial, antitumor and it also has a noteworthy role in the control of different diseases. In this review, we summarize the understanding of chemopreventive effects of curcumin in the prevention of cancer via the regulation of various cell signaling and genetic pathways.

The molecular basis for the pharmacokinetics and pharmacodynamics of curcumin and its metabolites in relation to cancer

This review addresses the oncopharmacological properties of curcumin at the molecular level. First, the interactions between curcumin and its molecular targets are addressed on the basis of curcumin's distinct chemical properties, which include H-bond donating and accepting capacity of the β-dicarbonyl moiety and the phenylic hydroxyl groups, H-bond accepting capacity of the methoxy ethers, multivalent metal and nonmetal cation binding properties, high partition coefficient, rotamerization around multiple C-C bonds, and the ability to act as a Michael acceptor. Next, the in vitro chemical stability of curcumin is elaborated in the context of its susceptibility to photochemical and chemical modification and degradation (e.g., alkaline hydrolysis). Specific modification and degradatory pathways are provided, which mainly entail radical-based intermediates, and the in vitro catabolites are identified. The implications of curcumin's (photo)chemical instability are addressed in light of pharmaceutical curcumin preparations, the use of curcumin analogues, and implementation of nanoparticulate drug delivery systems. Furthermore, the pharmacokinetics of curcumin and its most important degradation products are detailed in light of curcumin's poor bioavailability. Particular emphasis is placed on xenobiotic phase I and II metabolism as well as excretion of curcumin in the intestines (first pass), the liver (second pass), and other organs in addition to the pharmacokinetics of curcumin metabolites and their systemic clearance. Lastly, a summary is provided of the clinical pharmacodynamics of curcumin followed by a detailed account of curcumin's direct molecular targets, whereby the phenotypical/biological changes induced in cancer cells upon completion of the curcumin-triggered signaling cascade(s) are addressed in the framework of the hallmarks of cancer. The direct molecular targets include the ErbB family of receptors, protein kinase C, enzymes involved in prostaglandin synthesis, vitamin D receptor, and DNA.

Curcumin loaded poly(2-hydroxyethyl methacrylate) nanoparticles from gelled ionic liquid--in vitro cytotoxicity and anti-cancer activity in SKOV-3 cells

The main focus of this study is to encapsulate hydrophobic drug curcumin in hydrophilic polymeric core such as poly(2-hydroxyethyl methacrylate) [PHEMA] nanoparticles from gelled ionic liquid (IL) to improve its efficacy. We have achieved 26.4% drug loading in a biocompatible hydrophilic polymer. Curcumin loaded PHEMA nanoparticles (C-PHEMA-NPs) were prepared by nano-precipitation method. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis showed that the prepared nanoparticles were spherical in shape and free from aggregation. The size and zeta potential of prepared C-PHEMA-NPs were about 300 nm and -33.4 mV respectively. C-PHEMA-NPs were further characterized by FT-IR spectroscopy which confirmed the existence of curcumin in the nanoparticles. X-ray diffraction and differential scanning calorimetry studies revealed that curcumin present in the PHEMA nanoparticles were found to be amorphous in nature. The anticancer activity of C-PHEMA-NPs was measured in ovarian cancer cells (SKOV-3) in vitro, and the results revealed that the C-PHEMA-NPs had better tumor cells regression activity than free curcumin. Flow cytometry showed the significant reduction in G0/G1 cells after treatment with C-PHEMA-NPs and molecular level of apoptosis were also studied using western blotting. Toxicity of PHEMA nanoparticles were studied in zebrafish embryo model and results revealed the material to be highly biocompatible. The present study demonstrates the curcumin loaded PHEMA nanoparticles have potential therapeutic values in the treatment of cancer.

The effect of curcumin on breast cancer cells

Curcumin, which is extracted from the plant Curcuma longa, has been used in the therapeutic arsenal for clinical oncology. Curcumin has chemopreventive and antitumoral activities against some aggressive and recurrent cancers. The expressions and activities of various proteins, such as inflammatory cytokines and enzymes, transcription factors, and gene-products linked with cell survivals and proliferation, can be modified by curcumin. Moreover, curcumin decreases the toxic effect of mitomycin C. Though curcumin has shown highly cytotoxic to some cancer cell lines, curcumin is insoluble and instable in water. The solubility of curcumin could be enhanced by utilizing the solubilizing properties of rubusoside. In addition, the selective delivery of synthetic analogs or nanotechnology-based formulations of curcumin to tumors may improve the chemopreventive and chemotherapeutic effects. The focus of this short review is to describe how curcumin participates in antitumor processes in breast cancer cells.

Bisphenol-A-induced inactivation of the p53 axis underlying deregulation of proliferation kinetics, and cell death in non-malignant human breast epithelial cells

Widespread distribution of bisphenol-A (BPA) complicates epidemiological studies of possible carcinogenic effects on the breast because there are few unexposed controls. To address this challenge, we previously developed non-cancerous human high-risk donor breast epithelial cell (HRBEC) cultures, wherein BPA exposure could be controlled experimentally. BPA consistently induced activation of the mammalian target of rapamycin (mTOR) pathway—accompanied by dose-dependent evasion of apoptosis and increased proliferation—in HRBECs from multiple donors. Here, we demonstrate key molecular changes underlying BPA-induced cellular reprogramming. In 3/3 BPA-exposed HRBEC cell lines, and in T47D breast cancer cells, proapoptotic negative regulators of the cell cycle (p53, p21^WAF1 and BAX) were markedly reduced, with concomitant increases in proliferation-initiating gene products (proliferating cell nuclear antigen, cyclins, CDKs and phosphorylated pRb). However, simultaneous exposure to BPA and the polyphenol, curcumin, partially or fully reduced the spectrum of effects associated with BPA alone, including mTOR pathway proteins (AKT1, RPS6, pRPS6 and 4EBP1). BPA exposure induced an increase in the ERα (Estrogen Receptor): ERβ ratio—an effect also reversed by curcumin (analysis of variance, P < 0.02 for all test proteins). At the functional level, concurrent curcumin exposure reduced BPA-induced apoptosis evasion and rapid growth kinetics in all cell lines to varying degrees. Moreover, BPA extended the proliferation potential of 6/6 primary finite-life HRBEC cultures—another effect reduced by curcumin. Even after removal of BPA, 1/6 samples maintained continuous growth—a hallmark of cancer. We show that BPA exposure induces aberrant expression of multiple checkpoints that regulate cell survival, proliferation and apoptosis and that such changes can be effectively ameliorated.

The effect of curcumin on human bronchial epithelial cells exposed to fine particulate matter: a predictive analysis

Fine particulate matter (PM_2.5) has been associated in humans with inflammation, oxidative stress and cancer. Studies had shown that curcumin could potentially inhibit these effects; however, there had been no in vivo or in vitro reports about the effects of curcumin on organisms exposed to PM_2.5. This predictive study explored the possible biological functions and pathways involved in the mechanism of curcumin inhibition of the hazardous effects of PM_2.5. For predictive analysis, microarray data were used to investigate the effect of PM_2.5 on human bronchial epithelial cells (HBEC), and human target proteins of curcumin were retrieved from PubChem. Two protein-protein interaction (PPI) networks were established based upon differential genes and target proteins, respectively, and the common network of these two networks was found. Functional and pathway analysis of the common network was performed using the Ingenuity Pathways Analysis (IPA) software. The results suggested that the predictive effects of curcumin on HBEC exposed to PM_2.5 were involved in bio-functions, including inflammatory response of airway, cancerogenesis, and apoptosis, and in pathways such as cancer, glucocorticoid receptor signaling, and NF-kappaB signaling. This study predicted for the first time that curcumin could be a potential therapeutic agent for protecting the human airway from the hazardous effects of PM_2.5.

Effects of curcumin on global gene expression profiles in the highly invasive human breast carcinoma cell line MDA-MB 231: A gene network-based microarray analysis

Curcumin, or diferuloylmethane, is a major chemical component of turmeric (Curcuma longa Linn.) that has been consumed as a dietary spice through the ages. This yellow-colored polyphenol has a notably wide range of beneficial properties, including anti-inflammatory, antioxidant, antitumoral, anti-invasive and anti-metastatic activity. In the present study, microarray gene expression analysis was applied to identify the curcumin-regulated genes in a highly invasive human breast carcinoma cell line (MDA-MB 231). Cells were cultured with curcumin (20 μM) for 24 h; total RNA was isolated and hybridized to Whole Human Genome Microarray slides. Gene set enrichment analyses on our whole genome expression data revealed downregulation of the EGF pathway elements following curcumin treatment. Furthermore, gene network analysis identified a significantly relevant network among the differentially expressed genes, centered on the EGR1 and FOS genes. The members of these pathways and networks play an essential role in the regulation of cancer cell growth and development; the majority exhibited decreased expression levels following treatment with curcumin. These observations suggest that curcumin is an excellent candidate for the prevention and treatment of breast cancer.

Intraductal administration of a polymeric nanoparticle formulation of curcumin (NanoCurc) significantly attenuates incidence of mammary tumors in a rodent chemical carcinogenesis model: Implications for breast cancer chemoprevention in at-risk populations

Multiple lines of evidence support a role for curcumin in cancer chemoprevention. Nonetheless, despite its reported efficacy and safety profile, clinical translation of curcumin has been hampered by low oral bioavailability, requiring infeasible 'mega' doses for achieving detectable tissue levels. We have engineered a polymeric nanoparticle encapsulated formulation of curcumin (NanoCurc) to harness its full therapeutic potential. In the current study, we assessed the chemoprevention efficacy of NanoCurc administered via direct intraductal (i.duc) injection in a chemical carcinogen-induced rodent mammary cancer model. Specifically, Sprague-Dawley rats exposed to systemic N-methyl-N-nitrosourea were randomized to receive either oral free curcumin at a previously reported 'mega' dose (200mg/kg) or by direct i.duc injection of free curcumin or NanoCurc, respectively, each delivering 168 µg equivalent of curcumin per rodent teat (a ~20-fold lower dose per animal compared to oral administration). All three chemoprevention modalities resulted in significantly lower mammary tumor incidence compared with control rats; however, there was no significant difference in cancer incidence between the oral dosing and either i.duc arms. On the other hand, mean tumor size, was significantly smaller in the i.duc NanoCurc cohort compared with i.duc free curcumin (P < 0.0001), suggesting the possibility of better resectability for 'breakthrough' cancers. Reduction in cancer incidence was associated with significant decrease in nuclear factor -κB activation in the NanoCurc treated mammary epithelium explants, compared to either control or oral curcumin-administered rats. Our studies confirm the potential for i.duc NanoCurc as an alternative to the oral route for breast cancer chemoprevention in high-risk cohorts.

Curcumin inhibits protein phosphatases 2A and 5, leading to activation of mitogen-activated protein kinases and death in tumor cells

Curcumin can induce p53-independent apoptosis. However, the underlying mechanism remains to be defined. Here, we show that curcumin-induced apoptosis in a panel of tumor cells with mutant p53. Curcumin rapidly induced activation of the mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase 1/2 (Erk1/2) and c-Jun N-terminal kinase (JNK). Inhibition of JNK (with SP600125) or Erk1/2 (with U0126) partially prevented curcumin-induced cell death in the cells. Similarly, expression of dominant negative c-Jun or downregulation of Erk1/2 in part attenuated curcumin-induced cell death. It appears that curcumin-induced activation of MAPKs and apoptosis was due to induction of reactive oxygen species (ROS), as pretreatment with N-acetyl-L-cysteine, a ROS scavenger, blocked these events. Furthermore, we found that curcumin-induced activation of MAPK pathways was related to inhibition of the serine/threonine protein phosphatases 2A (PP2A) and 5 (PP5). Overexpression of PP2A or PP5 partially prevented curcumin-induced activation of JNK and Erk1/2 phosphorylation as well as cell death. The results suggest that curcumin induction of ROS activates MAPKs, at least partially by inhibiting PP2A and PP5, thereby leading to p53-independent apoptosis in tumor cells.

Dendrosomal curcumin significantly suppresses cancer cell proliferation in vitro and in vivo

Curcumin, the main compound of spice turmeric, is one of the natural products that has been shown to possess effective anti-cancer properties. However, the absorption efficacy of curcumin is too low to make dramatic results in therapy. Therefore, we based the main aim of this study on improving the bioavailability of curcumin taking advantage of dendrosome nanoparticles; and subsequently evaluating in vitro and in vivo anti-tumor properties of dendrosomal curcumin. In vitro studies were carried out utilizing A431 and WEHI-164 cell lines and mouse embryonic normal fibroblasts. Our data revealed that dendrosomal curcumin not only exhibits a much higher bioavailability than void curcumin (P<0.05) but also inhibits the proliferation of cancer cells (P<0.01) in a time- and dose-dependent manner that could be ascribed to the induction of apoptosis. However, dendrosome did not indicate any toxic effect on different types of cell lines. For in vivo studies, BALB/c tumor-bearing mice were treated with dendrosomal curcumin, void curcumin, dendrosome and PBS. The results indicated that dendrosomal curcumin reduces significantly the tumor size in comparison with void curcumin and control samples (P<0.05). Furthermore, in animals treated with dendrosomal curcumin a longer survival was observed (P<0.01). We also found that the mice treated with dendrosomal curcumin, showed a significant increase in splenocyte proliferation and IFN-γ production as well as a significant decrease in IL-4 production. This can be a proof of anti-tumor immunity caused by dendrosomal curcumin. The findings demonstrate that dendrosomal curcumin offers a great potential to be a promising anti-cancer therapeutic agent.

Enhanced drug loading on magnetic nanoparticles by layer-by-layer assembly using drug conjugates: blood compatibility evaluation and targeted drug delivery in cancer cells

Drug targeting using magnetic nanoparticles (MNPs) under the action of an external magnetic field constitutes an important mode of drug delivery. Low cargo capacity, particularly in hydrophobic drugs, is one limitation shown by MNPs. This article describes a simple strategy to enhance the drug-loading capacity of MNPs. The approach was to use polymer-drug conjugates to modify MNPs by layer-by-layer assembly (LbL). Curcumin (CUR) has shown remarkably high cytotoxicity toward various cancer cell lines. However, the drug shows low anticancer activity in vivo because of its reduced systemic bioavailability acquired from its poor aqueous solubility and instability. To address this issue, we synthesized cationic and anionic CUR conjugates by anchoring CUR onto poly(vinylpyrroidone) (PVP-Cur) and onto hyaluronic acid (HA-Cur). We used these oppositely charged conjugates to modify MNPs by layer-by-layer (LbL) assembly. Six double layers of curcumin conjugates were constructed on positively charged amino-terminated magnetic nanoparticles, TMSPEDA@MNPs. Finally, HA was coated onto the outer surface to form HA (HA-Cur/PVP-Cur)(6)@MNPs. Cellular viability studies showed the dose-dependent antiproliferative effect of HA (HA-Cur/PVP-Cur)(6)@MNPs in two cancer cell lines (glioma cells and Caco-2 cells). HA (HA-Cur/PVP-Cur)(6)@MNPs exhibited more cytotoxicity than did free curcumin, which was attributed to the enhanced solubility along with better absorption via hyaluronic acid receptor-mediated endocytosis. Flow cytometry showed enhanced intake of the modified MNPs by cells. Confocal microscope images also confirmed the uptake of HA (HA-Cur/PVP-Cur)(6)@MNPs with greater efficacy. Thus, the strategy that we adopted here appears to have substantial potential in carrying enhanced payloads of hydrophobic drugs to specified targets.

Gold nanoparticles generated and stabilized by water soluble curcumin-polymer conjugate: blood compatibility evaluation and targeted drug delivery onto cancer cells

Curcumin (Cur) shows low anticancer activity in vivo due to its reduced systemic bioavailability stemmed from its poor aqueous solubility and instability. Suitably functionalized nanocarriers designed to empty the drug specifically at tumor sites can potentially enhance the antitumor activity of Cur. We devised a simple method for the fabrication of water soluble Cur conjugated gold nanoparticles to target various cancer cell lines. Cur was conjugated to hyaluronic acid (HA) to get a water soluble conjugate (HA-Cur). We generated gold nanoparticles (AuNPs) by reducing chloroauric acid using HA-Cur, which played the dual role of a reducing and stabilizing agent and subsequently anchored folate conjugated PEG. These entities were probed using different analytical techniques, assayed the blood compatibility and cytotoxicity. Their interaction with cancer cell lines (HeLa cells, glyoma cells and Caco 2 cells) was followed by flow cytometry and confocal microscopy. Blood-materials interactions studies showed that the nanoparticles are highly hemocompatible. Flow cytometry and confocal microscopy results showed significant cellular uptake and internalization of the particles by cells. HA-Cur@AuNPs exhibited more cytotoxicity comparing to free Cur. The strategy, we adopted here, resulted the formation blood compatible Cur conjugated AuNPs with enhanced targeting and improved efficacy.

Curcumin chemoprevention: the long road to clinical translation

Curcumin exhibits significant antitumorigenic activity in various preclinical models; data supporting its chemopreventive activity in humans, however, are lacking. To our knowledge, the first published results of a phase II chemoprevention study of curcumin are reported in this issue of the journal by Carroll and colleagues (beginning on page 354), who examined the effects of oral curcumin on various putative biomarkers of colonic tumorigenesis in smokers. This perspective discusses the potential significance and limitations of the current study findings in addressing the question of whether curcumin is clinically active as a chemopreventive agent.

Conjugation of curcumin onto hyaluronic acid enhances its aqueous solubility and stability

Polymer-drug conjugates have gained much attention largely to circumvent lower drug solubility and to enhance drug stability. Curcumin is widely known for its medicinal properties including its anticancer efficacy. One of the serious drawbacks of curcumin is its poor water solubility which leads to reduced bioavailability. With a view to address these issues, we synthesized hyaluronic acid-curcumin (HA-Cur) conjugate. The drug conjugate was characterized using FT-IR, NMR, Dynamic light scattering and TEM techniques. The conjugates, interestingly found to assembles as micelles in aqueous phase. The formation of micelles seems to improve the stability of the drug in physiological pH. We also assessed cytotoxicity of the conjugate using L929 fibroblast cells and quantified by MTT assay.

Synthesis and characterization of a cytotoxic cationic polyvinylpyrrolidone-curcumin conjugate

Curcumin has been studied as a potential drug for many diseases including cancer. One of the serious limitations projected on curcumin is its poor water solubility and the substantially low bioavailability. With a view to enhance the aqueous solubility of curcumin, we synthesized polyvinylpyrrolidone-curcumin conjugates. Polyvinylpyrrolidone was used for the conjugation considering its long history of safe usage as a biomaterial for various medical applications. The drug conjugates self-assembled in aqueous solution to form nanosized micellar aggregates. The formation of micellae stabilized curcumin against hydrolytic degradation. Another interesting feature of the conjugate was its cationic nature. The net zeta potential in the pH range from 3 to 7.4 was +25 to +20 mV, reflecting the potential stability of the conjugate micellae at physiological pH. We quantified cytotoxic potential of the conjugate by the MTT assay, using L929 fibroblast cells. The results showed that the conjugate had higher cytotoxicity than that of the free curcumin. It is expected that the relative enhanced cytotoxicities are the result of enhanced aqueous solubility and polymer-mediated drug internalization. The conjugate has the potential to circumvent limitations of curcumin and thereby to extrapolate further its applications as an effective anticancer drug.